- TEST_SPEC.md: Updated test directory structure to reflect Core/Asset,
Core/IO, and Resources/<Type> subdirectories
- TEST_SPEC.md: Updated module names and test counts (852 total)
- TEST_SPEC.md: Updated build commands for new Resources subdirectories
- README.md: Updated engine structure with Core/Asset/ and Core/IO/
- README.md: Updated Resources section with layered architecture
- README.md: Updated test coverage table with accurate counts
